Thameslink: Next Stop London Bridge!

Last spring, the rail engineer gave an update on the progress of the challenging £5.5 billion scheme to improve the Thameslink route through the heart of London from Bedford to Brighton. At the time, the Shard was just becoming a recognised feature of the landscape although it still wasn’t completed. It was also the time when everyone was looking over their shoulder excitedly, albeit with some trepidation, at the prospect of the London Olympics – a success or a national embarrassment?

Now however, for the not inconsiderable sum of £24.95, one can take a ride up to the top of the Shard and admire the view knowing that the Olympic Games were delivered on time and without incident, providing the country with something to be proud of. Down at ground level, work has progressed steadily to ensure that the Thameslink project continues to plan and budget, improving the journey for many thousands of commuters.

That project is now at the halfway stage and work is progressing well. Chris Binns is Network Rail’s head of engineering for the Thameslink programme and he is clearly still very enthusiastic about the project. He was eager to give a general update on progress, plus an outline of the next phases of work that will lead up to its completion in 2018.

Progress

The redesign of Farringdon station is now complete. Many buildings, including a 14 storey office block, have been demolished without incident, platforms extended to accommodate the 12 car trains and a new footbridge constructed to improve passenger connections with London Underground.

The existing station roof has been extended by 60 metres and an impressive new ticket hall added to the south. New lift shafts have been constructed that extend down to a level which will form part of the Crossrail service, linking into the station when the tunnel boring machines reach the station area sometime later in the year.

Blackfriars station has been dramatically revamped with its unique access points on both banks of the Thames. Chris wanted to emphasise that the station was opened to passengers in time for the Olympics in accordance with the plan. The installation of more than four thousand solar panels throughout the length of the newly constructed station canopies is now complete and delivering power into the station complex.

Balfour Beatty is the principal contractor for this work and Network Rail has recently completed additional structural repair work to the 1869 Grade 2 listed, five span arch bridge that supports the new platforms and station canopies. While already functionally complete, the final installation of glazing panels, waterproofing and snagging at the station are expected to be completed by the late summer.

Chris recalled the challenges that the short stretch of railway between Blackfriars and London Bridge stations posed for the team and he was delighted that they are now resolved to everyone’s satisfaction. This part of the project has certainly concentrated minds throughout, since there has been a need to extend the two track railway to four tracks through a short 350 metre corridor running alongside Southwark cathedral, over Borough Market and across the High Street before passing alongside the Shard and into the station complex at London Bridge.

Preparation for four tracks

It was a site that archaeologists as well as engineers wanted access to and some significant archaeological finds were made before the new structure was built by Skanska. The structure consists of six continuous spans of double track bridge with I-girders supporting transverse steel-concrete cross-girders with a concrete slab deck. In addition, a single span tubular steel bridge crosses Borough High Street leading up to the station. Just like the Shard, it is now part of the landscape spanning the beautifully revamped Victorian roof of Borough market and the recently reopened Wheatsheaf public house, minus its top storey! The plan is to bring the viaduct into use by August 2015.

An immense amount of planning and preparation has gone into both these landmark features and other work not detailed here including platform extensions, structural modification, track and signalling. At Borough Market alone there were 247 ‘party wall’ agreements produced and at one stage there were nearly 700 Network Rail delivery staff working on the Thameslink programme. This has now settled down to just fewer than 400 which, Chris thinks, will be the number required for the remainder of the project.

Conflicting movements

So, that’s the story so far. Currently underway is the total redevelopment of London Bridge station alongside essential changes to the track layout both east and west. To the east, work will extend out to the New Cross Gates area and include a new structure known as the Bermondsey Dive Under which will be completed by 2016. This will enable Thameslink trains to travel over Charing Cross lines without conflicting moves. Also, the track layout to the west will be reconfigured to ensure that Thameslink trains will be able to travel round into Blackfriars station independent of other train movements.

The team has full authority to proceed with this next stage with approval given by Network Rail and Department for Transport boards last November and receipt of ‘a letter of no objection’ from the Office of Rail Regulation in December. Costain has been appointed as the principal contractor for the station work by Network Rail, supported by WSP and Hyder Consulting for the design work. Balfour Beatty Rail has been appointed as principal contractor for all the track work and Invensys has been awarded the complex signalling design and installation contract, working with a dedicated Network Rail signalling design team for commissioning stage-works and fringe interface issues.

The architect for London Bridge station is Grimshaw and their remit has been to convert the existing split level, highly congested station with its six through and nine terminating platforms into one single level station with nine through and six terminating platforms all linked by escalators and lifts to an open concourse. The plan is for Platforms 4 and 5 to be dedicated to Thameslink and the new proposed track layout is designed accordingly.

Spacious concourse

To achieve this vision, Network Rail decided to go underground amongst the maze of Dickensian arches and this is where the new concourse will be constructed. It will extend right across the station from north to south running at right angles to the tracks. The space it will create is significant with football pitch proportions.

The platforms will be supported on viaducts over the concourse area and each platform will be protected from the elements by a simple canopy structure. Where the canopies span the concourse, northern light glazing will be included to ensure that the concourse area is light as well as weather proof.

High quality brickwork walls and arches will be constructed on the outside of the station both along Tooley Street to the north and St Thomas Street to the south. Everything will be brand new and, seen from overhead, the glistening new station platform canopies should appear as shining roots of the shard above. That will be impressive and if it works, it could justify the £24.95 ticket! It all sounds quite straight forward but there is just one minor detail to consider – how do you build the new station without interfering with day to day activities and allow London commuters to use the existing facilities, preferably throughout the whole of the project?

The answer is with great difficulty. However, so far, more than 50% of the old train shed roof has already been removed without any problem. A temporary crash deck has been constructed to protect passengers allowing the work to continue.

Staging diagrams

The team have produced detailed staging diagrams that cover all the work throughout the whole period from 2013 up to 2018. The detailed diagrams produced over the last two years of development go through ten key integrated station and track remodelling stages underpinned by large folders of detailed charts showing staging sequences and diagrams detailing each event down to the hour.

A minimum 14 day buffer has been built into each critical stage of the programme – one of the many lessons learnt through experience, something the team has been keen to do. Another example is that there is no longer any “man-marking” within the London Bridge station project. Instead, the most suitable person for the job is appointed, irrespective of their employer. So, where appropriate, Network Rail personnel will take instruction from Costain managers and vice versa. It all depends on what that team members have to offer, not who they work for.

According to Chris Binns, it is this partnering approach that will ensure that the project will be delivered on time and to budget. Also, it is the complexity of the project and the need to provide the level of detail necessary throughout the project that he and the team find so fascinating. Absolutely everything that is planned has a knock on effect which has to be understood, communicated, recorded and managed. As Chris emphasised, there is no other project quite like it and attention to every detail is absolutely essential.

New trains

Some actions are not within the direct control of the project team but are integrated into their plans. Enabling works are now underway to provide connections into the train depots required at Three Bridges on the Brighton line and Hornsey on the ECML in preparation for the arrival of the Class 700 although the DfT is responsible for providing the trains, the depot and of course, the Thameslink franchise itself.

Real progress is being made and so far Thameslink has delivered 12-car capabilities on the Midland Mainline and through the core area between St Pancras and Blackfriars. This includes major station rebuilding at Farringdon and Blackfriars. The railway systems in this area have also been upgraded to support the final capacity requirements that will eventually be delivered. It is good news so far.

The complete rebuild of London Bridge station will increase capacity for thousands of travellers during peak periods and, with the new Dive Under at Bermondsey plus the significant track realignment and associated signalling work, it will offer a logical path for trains, removing the conflicting movements that have frustrated train operators over the years.

There is a long way to go and many more engineering stories to tell but, with the enthusiasm displayed by Chris on behalf of the team, there is plenty of room for optimism.

Collin Carr studied civil engineering at Swansea University before joining British Rail Eastern Region as a graduate trainee in 1975.

Following various posts for the Area Civil Engineer in Leeds, Collin became Assistant Engineer for bridges, stations and other structures, then P Way engineer, to the Area Civil Engineer in Exeter. He then moved on to become the Area Civil Engineer Bristol.

Leading up to privatisation of BR, Collin was appointed the Infrastructure Director for InterCity Great Western with responsibility for creating engineering organisations that could be transferred into the private sector in a safe and efficient manner. During this process Collin was part of a management buyout team that eventually formed a JV with Amey. He was appointed Technical Director of Amey Rail in 1996 and retired ten years later as Technical Transition Director of Amey Infrastructure Services.

Now a self-employed Consultant, Collin has worked with a number of clients, including for RSSB managing an industry confidential safety reporting system known as CIRAS, an industry-wide supplier assurance process (RISAS) and mentoring and facilitating for a safety liaison group of railway infrastructure contractors, the Infrastructure Safety Leadership Group (ISLG).

One Comment

It always seemed surprising to me that no attempt seems to have been made to have the London Bridge through platforms aligned by direction rather than use - that could only be done for two rather than three routes of course but the facility to go (say) from Croydon to Charing Cross or Dartford to St Albans cross platform would be a valuable one. Given that a bridge is already being provided in Bermondsey only a single line bridge parallel to the spur at Ewer Street would be required.